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A meshless local Petrov–Galerkin method for solving the neutron diffusion equation

nuclear Science and Techniques 2018年第11期29卷 304-322页

作者： Shima Tayefi Ali Pazirandeh Mohsen Kheradmand Saadi department of nuclear engineering Science and Research BranchIslamic Azad University

The goal of this study is to solve the neutron diffusion equation by using a meshless method and evaluate its performance compared to traditional methods. This paper proposes a novel method based on coupling the meshless local Petrov–Galerkin approach and the moving least squares approximation. This computational procedure consists of two main steps. The first involved applying the moving least squares approximation to construct the shape function based on the problem domain. Then, the obtained shape function was used in the meshless local Petrov–Galerkin method to solve the neutron diffusion *** the meshless method is based on eliminating the mesh-based topologies, the problem domain was represented by a set of arbitrarily distributed nodes. There is no need to use meshes or elements for field variable interpolation. The process of node generation is simply and fully automated, which can save time. As this method is a local weak form, it does not require any background integration cells and all integrations are performed locally over small quadrature domains. To evaluate the proposed method,several problems were considered. The results were compared with those obtained from the analytical solution and a Galerkin finite element method. In addition, the proposed method was used to solve neutronic calculations in thesmall modular reactor. The results were compared with those of the citation code and reference values. The accuracy and precision of the proposed method were acceptable. Additionally, adding the number of nodes and selecting an appropriate weight function improved the performance of the meshless local Petrov–Galerkin method. Therefore, the proposed method represents an accurate and alternative method for calculating core neutronic parameters.

关键词： Neutron diffusion equation Meshless local Petrov–Galerkin(MLPG) Moving least squares approximation(MLSA) Meshless methods

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Selected topics of quantum computing for nuclear physics

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Chinese Physics B 2021年第2期30卷 23-34页

作者： Dan-Bo Zhang Hongxi Xing Hui Yan Enke Wang Shi-Liang Zhu Guangdong Provincial Key Laboratory of quantum engineering and quantum Materials School of Physics and Telecommunication EngineeringSouth China Normal UniversityGuangzhou 510006China Guangdong-Hong Kong Joint Laboratory of quantum Matter Frontier Research Institute for PhysicsSouth China Normal UniversityGuangzhou 510006China Guangdong Provincial Key Laboratory of nuclear Science Institute of Quantum MatterSouth China Normal UniversityGuangzhou 510006China Guangdong-Hong Kong Joint Laboratory of quantum Matter Southern Nuclear Science Computing CenterSouth China Normal UniversityGuangzhou 510006China

nuclear physics,whose underling theory is described by quantum gauge field coupled with matter,is fundamentally important and yet is formidably challenge for simulation with classical *** computing provides a perhaps transformative approach for studying and understanding nuclear *** rapid scaling-up of quantum processors as well as advances on quantum algorithms,the digital quantum simulation approach for simulating quantum gauge fields and nuclear physics has gained lots of *** this review,we aim to summarize recent efforts on solving nuclear physics with quantum *** first discuss a formulation of nuclear physics in the language of quantum *** particular,we review how quantum gauge fields(both Abelian and non-Abelian)and their coupling to matter field can be mapped and studied on a quantum *** then introduce related quantum algorithms for solving static properties and real-time evolution for quantum systems,and show their applications for a broad range of problems in nuclear physics,including simulation of lattice gauge field,solving nucleon and nuclear structures,quantum advantage for simulating scattering in quantum field theory,non-equilibrium dynamics,and so ***,a short outlook on future work is given.

关键词： quantum computing nuclear physics quantum field theory quantum simulation quantum algorithm

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Application of fractal characteristic quantities of pressure fluctuation in subcooled boiling regime recognition

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nuclear Science and Techniques 2001年第4期12卷 309-318页

作者： KUANG Bo, XU Ji-Jun (department of nuclear Power engineering and Automation, Shanghai Jiaotong University, Shanghai 200030) engineering department of nuclear Power engineering and Automation Shanghai Jiaotong University.

The dynamical behavior of the subcooled boiling two-phase system was introduced and discussed. With the introduction of fractal concept, an analysis of the fractal feature of pressure wave signals from nonlinear dynamics point of view, was carried out. Meanwhile, the pseudo phase diagrams of typical time series of sound pressure were given. Finally, through dynamic clustering and on the basis of calculating correlation dimension and Hurst exponent of pressure wave time series on different subcooling conditions, the recognition of developing regime of the two-phase system was delivered, which might provide a promising approach of recognition and diagnosis of a boiling system.

关键词：核反应堆过冷锅炉热声效应

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Control system design for a pressure-tube-type supercritical water-cooled nuclear reactor via a higher order sliding mode method

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nuclear Science and Techniques 2024年第1期35卷 145-154页

作者： M.Hajipour G.R.Ansarifar department of nuclear engineering Faculty of PhysicsUniversity of IsfahanIsfahan 81746-73441Iran

nuclear power plants exhibit non-linear and time-variable ***,designing a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor(SCWR)is a fourth-generation conceptual *** an SCWR,the non-linear dynamics of the reactor require a controller capable of control-ling the *** this study,a pressure-tube-type SCWR was controlled during reactor power maneuvering with a higher order sliding mode,and the reactor outgoing steam temperature and pressure were controlled *** an SCWR,the temperature,pressure,and power must be maintained at a setpoint(desired value)during power *** point kinetics equations with three groups of delayed neutrons were used in the ***-order and classic sliding mode controllers were separately manufactured to control the plant and were compared with the PI controllers speci-fied in previous *** controlled parameters were reactor power,steam temperature,and ***,for these parameters,the PI controller had certain instabilities in the presence of *** classic sliding mode controller had a higher accuracy and stability;however its main drawback was the chattering *** was highly accurate and stable and had a small computational *** reality,it followed the desired values without oscillations and chattering.

关键词： Supercritical water nuclear reactor Higher order sliding mode controller Steam temperature Steam pressure Point kinetics model

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Breakup of spherical vesicles caused by spontaneous curvature change

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Acta Mechanica Sinica 2012年第6期28卷 1545-1550页

作者： Ping Liu Ju Li Yong-Wei Zhang Institute of High Performance Computing department of nuclear Science and engineering Massachusetts Institute of Technology

We present our theoretical analysis and coarse- grained molecular dynamics （CGMD） simulation results to describe the mechanics of breakup of spherical vesi- cles driven by changes in spontaneous curvature. System- atic CGMD simulations reveal the phase diagrams for the breakup and show richness in breakup morphologies. A the- oretical model based on Griffith fracture mechanics is devel- oped and used to predict the breakup condition.

关键词： Molecular dynamics Bending modulus Phasediagram. Fracture

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Structures and magnetic anisotropy of β-Mn_2V_2O_7 crystals synthesized by the molten salt method

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Chinese Physics B 2009年第11期18卷 5055-5060页

作者：周传仓刘发民丁芃 department of Physics School of Physics and Nuclear Energy EngineeringBeijing University of Aeronautics and Astronautics

β-Mn2V2O7 crystals with strip shape are successfully prepared by the molten salt method in a closed crucible, and are characterized by x-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, selected area of electron diffraction （SAED） and high-resolution transmission electron microscopy （HRTEM）. The results indicate that the sample is of the β-Mn2V2O7 crystal with monoclinic symmetry, level natural cleavage facets and directional growth. Magnetic properties are measured by vibration sample magnetometry （VSM） at room temperature, and the magnetic hysteresis loop indicates that the β-Mn2V2O7 has anti-ferromagnetic properties with low coercive force and remnant magnetization. The magnetic measurement results in different directions exhibit that the β-Mn2V2O7 has magnetic anisotropy, which is due to the fact that the magnetic interaction energy of the β-Mn2V2O7 is lowest only when the electron configuration is in a certain direction.

关键词： β-Mn2V2O7 molten salt synthesis magnetic anisotropy

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Modeling Dysentery Diarrhea Using Statistical Period Prevalence

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Computer Modeling in engineering & Sciences 2021年第7期128卷 183-201页

作者： Fouad A.Abolaban department of nuclear engineering College of EngineeringKing Abdulaziz UniversityJeddah21589Saudi Arabia

Various epidemics have occurred throughout history,which has led to the investigation and understanding of their transmission *** a result,non-local operators are used for mathematical modeling in this ***,this research focuses on developing a dysentery diarrhea model with the use of a fractional operator using a one-parameter Mittag–Leffler *** model consists of three classes of the human population,whereas the fourth one belongs to the pathogen *** model carefully deals with the dimensional homogeneity among the parameters and the fractional *** addition,the model was validated by fitting the actual number of dysentery diarrhea infected cases covering 52 weeks in 2017,which occurred in *** biological parameters were fitted,and fractional orderνwas *** basic reproduction numbers R0 were 1.7031 and 1.9581,which correspond to the fractional and integer-order models,*** fractional model showed smaller discrepancies compared to the integer-order model when the models were fitted and validated with the actual cases of infected *** theory for the existence and uniqueness of the solutions was extensively explored,and the stability of equilibria was *** most influential parameters were found via forward sensitivity *** multidisciplinary research shows and explains the results of numerical simulations applied to a biological issue.

关键词： Dysentery diarrhea model Mittag–Leffler kernel fractional operator

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DPM simulation in an underground entry: Comparison between particle and species models

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International Journal of Mining Science and Technology 2016年第3期26卷 487-494页

作者： Thiruvengadam Magesh Zheng Yi Tien Jerry C. department of Mining & nuclear engineering Missouri University of Science & Technology Division of Mining and Resources engineering Department of Civil Engineering Monash University

The diesel particulate matter(DPM) emission from diesel powered equipment in underground mines can cause health hazards including cancer to the miners. The understanding of the DPM propagation pattern under realistic mining condition is required for selecting proper DPM control strategies and to improve working practices in underground mines. In this paper, three dimensional simulations of DPM emission from the exhaust tail pipe of a load-haul-dump(LHD) vehicle and its subsequent distribution inside an isolated zone in the typical underground mine are carried out using two different solution models available in Ansys Fluent. The incoming fresh air into the isolated zone is treated as a continuous phase and DPM is treated either as a continuous phase(gas) or as a secondary discrete phase(particle). Species transport model is used when DPM is treated as gas and discrete phase model is used when DPM is assumed to behave like a particle. The distributions of DPM concentration inside the isolated zone obtained from each method are presented and compared. From the comparison results, an accurate and economical solution technique for DPM evaluation can be selected.

关键词： CFD Dead-end DPM Discrete phase model Species transport model

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Electrochemical behavior of Pd(Ⅱ) and Rh(Ⅲ) in [EMIm]NTf_2 ionic liquid

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nuclear Science and Techniques 2015年第1期26卷 93-97页

作者：顾帅王欣鹏韦悦周方百增 School of nuclear Science and engineering department of Chemical & Biological engineering University of British Columbia

The electrochemical behavior of Pd(Ⅱ) and Rh(Ⅲ) in [EMIm]NTf2ionic liquid has been studied on Pt working electrodes at 298 K by cyclic voltammetry(CV), polarization curve and galvanostatic transient *** voltammogram of Pd(II) in [EMIm]NTf2consists of two cathodic current peaks located at 1.37 V(E pc2),corresponding to Pd2+/Pd+, and at 0.69 V(E pc1) corresponding to Pd+/Pd. The transfer coefficient α was calculated by the Tafel extrapolation from the polarization curves to be 0.306, which is in agreement with the value reported in an aqueous solution system. For Rh(Ⅲ) in [EMIm]NTf2, a cathodic current peak(E pc) was observed at-0.39 V, corresponding to Rh3+/Rh, and two oxidation peaks were observed at-0.13 V(E pa1) and0.37 V(E pa2) during the reverse scan. A significantly negative shift in the cathodic peak potential was observed with the increase of the scan rate, indicating that the reduction of Pd(II) and Rh(Ⅲ) on the Pt electrode involves kinetic complications. By using the galvanostatic transient technique, the diffusion coefficients of Pd(II) and Rh(Ⅲ) in [EMIm]NTf2ionic liquid solution were found to be ～ 10-7cm2/s. The potential difference between the reduction of Pd(II) to Pd and the reduction of Rh(Ⅲ) to Rh obtained from the CV curves of the Pd(II) and Rh(Ⅲ) co-existing [EMIm]NTf2solution is found to be about 0.74 V, which makes it possible to electrodeposit Pd(II) and Rh(Ⅲ) separately.

关键词：钯(Ⅱ) 电化学行为离子液体 III Rh 极化曲线溶液系统循环伏安

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Molecular dynamics study of temperature-dependent ripples in monolayer and bilayer graphene on 6H-SiC surfaces

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Chinese Physics B 2012年第6期21卷 413-420页

作者：唐超魏晓林谭歆彭向阳孙立忠钟建新 department of Physics&Key Laboratory for quantum engineering and Micro-Nano Energy Technology Xiangtan University

Using classical molecular dynamics and a simulated annealing technique, we show that microscopic corrugations occur in monolayer and bilayer graphene on 6H-SiC substrates. From an analysis of the atomic configurations, two types of microscopic corrugations are identified, namely periodic ripples at room temperature and random ripples at high temperature. Two different kinds of ripple morphologies, each with a periodic structure, occur in the monolayer graphene due to the existence of a coincidence lattice between graphene and the SiC terminated surface （Si- or C-terminated surface）. The effect of temperature on microscopic ripple morphology is shown through analysing the roughness of the graphene. A temperature-dependent multiple bonding conjugation is also shown by the broad distribution of the carbon-carbon bond length and the bond angle in the rippled graphene on the SiC surface. These results provide atomic-level information about the rippled graphene layers or~ the two polar faces of the 6H-SiC substrate, which is useful not only for a better understanding of the stability and structural properties of graphene, but also for the study of the electronic properties of graphene-based devices.

关键词： ripples graphene molecular dynamics

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